In a provocative comparison, Patricia Fara declares that "Official accounts of Soviet Russia avoided mentioning Josef Stalin. In contrast, women have not been written out of the history of science: they have never been written in." Women may have been excluded from the traditional historical record, but it is simply not the case, Fara demonstrates, that they were excluded from scientific activity in the 18th century. Pandora's Breeches presents so many examples of women active in science that the pronouncements of those who declared women were unscientific seem less like an injunction than a desperate attempt to lock the door after the horse has bolted.

In iconography and metaphor, women figured as symbols of knowledge, or as the object of knowledge, but in practical terms, they were not supposed to conduct scientific investigation themselves. Francis Bacon, the great 17th-century promoter of empirical natural philosophy, conceived of science as the masculine penetration and conquest of feminine Nature. However, reality did not reproduce the propaganda. Fara details a range of ways women were involved in science - or natural philosophy, as it was called. In most cases, the way to science was through a man. In aristocratic households, women often had access to their brothers' tutors and their fathers' libraries. Some, like intellectually ambitious gentlemen, amassed natural-history collections. Others corresponded with philosophers and even influenced their thinking.

Women might also participate in conversations with scientific guests and, in exceptional cases, preside over a learned salon. Thus they could not only engage in conversations about the latest scientific theories and discoveries, but act as patrons and further the career of male scientists. In England, Margaret Cavendish, Duchess of Newcastle, and in France, Marie Paul Lavoisier presided over such salons and made a name for themselves as scientific adepts. In the case of the Duchess of Newcastle, the name that stuck was "Mad Madge". Fara also introduces us to women who kept the detailed records of experiments or observations that enabled their husbands or brothers to pursue further research, or who supervised and fed the numerous assistants and artisans who supported experimentation. They might assist in experiments or, like the women associated with the French astronomer Joseph Lalande, undertake tedious mathematical calculations to demonstrate the findings of others. Sally Wedgwood was one of many involved in the development of techniques and materials that would have commercial applications. Several women translated key scientific texts or adapted them for younger audiences and thus facilitated the spread of science. Jane Marcet's educational dialogue, Conversations on Chemistry (1806), so captured the imagination of the young Michael Faraday that she inspired him to undertake his pioneering career.

What facilitated the involvement of women was the fact that, in this pre-professional age, science was not carried out in industrial and university laboratories but in the home. Most of the scientific work they did was supportive and secondary rather than pioneering; it was in some respects an extension of their existing domestic roles. Caroline Herschel, the first woman to publish papers in the Philosophical Transactions and the first woman to receive a salary for her scientific work, voluntarily acted as a drudge for her brother William and, when he died, her nephew John. The 17th-century campaigner for women's education, Bathsua Makin, argued that domestic science involved natural philosophy. If chemistry is cooking for boys, cooking is chemistry for girls. However, by suggesting they were capable of rational activity, women also transgressed the bounds of feminine decorum.

The woman of science is a hybrid, an unnatural figure, divided from her sex by her intellect and unable to join male institutions because of her gender. The title of the book alludes to the fear that when women wear the trousers, a host of evils will be unleashed on the world. Kant spluttered that "a woman who... conducts learned controversies on mechanics like the Marquise de Chatelier might as well have a beard". Emilie du Chtelet, whose translation of Newton made a big impact on French thought and whose Foundations of Physics was an ambitious synthesis of the theories of Newton, Descartes and Leibniz, certainly could conduct learned controversies on mechanics - and other subjects. But she did not conform to the stereotype of the de-feminised learned woman. Her fondness for dress and decoration did not meet with people's expectations. Her lover Voltaire acknowledged the impossibility of her position: she was, he declared, "a great man whose only fault was being a woman".

Finding out that, contrary to received wisdom, women actually did play a part in the scientific Enlightenment gives rise to the problem of how to write them back into history. How do we make sense of this knowledge? The aim of this book is not just to present information that will be new to most general readers, but also to reflect on how past histories of science have been written and how they might be written in future. It's all a question of framing. Fara complains that, while traditional histories of science have written women out because they have largely been histories of great men or big ideas, feminist histories are at fault for abstracting scientific women from their cultural contexts. She points out that national differences presented women with various opportunities: in France, women were seen as complementary to men and accorded more respect as rational beings; in Germany, the guild tradition enabled women to work in family trades; in England, well, women had to struggle.

Feminist historians, by treating women in science as pioneers, have created anachronistic collections of heroines, like cabinets of curiosities. Fara's aim is to change the history of science at a more fundamental level: "Rather than creating new female heroines, [ Pandora's Breeches ] has undermined conventional views of the past by attacking the very concept of heroism in science. This book has presented new interpretations of scientific men as well as of scientific women... Science is a collaborative project whose successes - and failures - can only be appreciated by understanding how scientific technology has permeated the whole of society."

This has the air of a publisher's blurb, but Fara does make good her rhetorical claims. Her contention about the collaborative nature of science is enshrined in the structure of her book, a structure that is at once intricate and solid. In thematic sections, she tackles the ideology of science; the "great men" view of history; science as part of everyday life; and the relation between science and the imagination. To explore each of these themes, she looks at exemplary pairs slashed together, such as Elisabeth of Bohemia/ René Descartes; Caroline Herschel/William Hershel; and Priscilla Wakfield/Carl Linnaeus. (What does the slash do? Make them equivalent, link them or divide them?) Each chapter opens with a summary of "traditional" accounts of male scientists and reframes our view by detailed examination of emblematic images such as portraits, frontispieces and scientific illustrations.

Fara's history foregrounds and makes a virtue of its construction: this is one way of telling the story, it declares, but there are others. This method might sometimes be heavy-handed but it is an excellent way of including women without doing men down. Fascinating in its details, Pandora's Breeches is also ground-breaking in the way it reframes the history of science.

Judith Hawley is the general editor of Literature and Science, 1660-1834, published by Pickering & Chatto.